/Engine/Plugins/Runtime/OpenXR/Source/OpenXRHMD/Public/IOpenXRExtensionPlugin.h
Add any actions provided by the plugin to Actions. This allows a plugin to 'hard code' an action so that the plugin can use it.
virtual void AddActions ( XrInstance Instance, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< XrAction(XrActionType InActionType, const [FName](API\Runtime\Core\UObject\FName) &InName, const [TArray](API\Runtime\Core\Containers\TArray)< XrPath > &InSubactionPaths)> AddAction )